VIDEO: Diesel vs Hybrid, the heavyweights take it to the streets
In another of the ongoing rounds between diesel versus hybrid we bring you two heavyweight contenders, the Chevy Tahoe hybrid, which we had in the AutoblogGreen garage, versus the Mercedes-Benz GL320 CDI. Actually, it's brought to you by the good folks at Edmunds who took it upon themselves to give these two a through shakedown. As I'm sure you've already noticed, these are two humongous SUVs that we don't consider especially green but for those folks who need to tow large trailered objects or haul large families they are relatively more green than their forebears.
The competition between these two was pretty tight for a while. Pricewise, the Mercedes was only $480 more than the Chevy for the base model though the Chevy became a pretty good bargain once the options came into play. Both of the beasts excelled at acceleration (8.5 second, 0-60) with the Tahoe ahead by the slimmest of whiskers as long as they traveled in a straight line. With the cones set up, the Mercedes superior agility really shone, whipping through the course at 60 mph while the Tahoe had more waddle than a flock of ducks on the hoof. Also, in the all important fuel economy category, the diesel pulled decisively ahead, at one point returning 26 mpg during a stretch of highway driving where the Tahoe could "only" eke out a 21.9 figure over that same stretch. Advantage diesel. To watch these two duke it out auto à auto, hit the jump.
Reader Comments (Page 1 of 1)
Temple 1:29PM (4/29/2008)
Damn, only if diesel prices weren't so damn high these days, especially compared to regular unleaded. I was thinking about getting a TDI but ridiculous diesel prices have curbed my enthusiasm since it eats into the cost benefit of getting the diesel in the first place.
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Phil L. 1:37PM (4/29/2008)
Let's re-do the fuel consumption in "miles per dollar" instead of "miles per gallon".
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Lee 1:59PM (4/29/2008)
Still find the diesel/gas debate silly because hybrids can use diesel, gas, ethanol or cow poop engines.
There are some $ differences but that hardly makes them diesel/gas different animals.
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BlackbirdHighway 2:35PM (4/29/2008)
Diesel getting 26 mpg at $4.20 a gallon works out to 16.15 cents per mile, while the gas burner at 21.9 mpg and $3.60 a gallon works out 16.43 cents per mile.
Still advantage Merc, but not by much. Does the Tahoe need premium or regular?
Wait, what am I saying? Everyone is using regular now, regardless of what the manufacturer says.
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carnut 2:57PM (4/29/2008)
The comparison looks biased to favor diesels IMHO. Hybrids really shine in city-type driving, yet I did not see a number in city driving for the diesel. Again, these cars cannot have the same emissions either (one is PZEV, the other is barely Tier 2 Bin 5, which is not even SULEV, which is Tier 2 Bin 2).
So, when you equate emissions - and this is important - you will further lose fuel economy in a diesel (5-7%). Furthermore, you should do a grams of CO2 / km comparison, because diesel carries 12% more CO2 per gallon (it's 12% heavier than gas). Additionally, no technology exists today that will make a diesel a PZEV.
But then again, this is not a technical paper or publication. So, everyone can just go on spreading misinformation and feeling well-informed...
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Chris 3:30PM (4/29/2008)
I think it's interesting that the MPG difference between these two vehicles (18.72% using 21.9MPG vs 26MPG) is within 1.2% of the price difference between Regular gas vs. Diesel using today's prices(17.66% using $3.607 vs. $4.244).
Fun with numbers...
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1985 Gripen 4:12PM (4/29/2008)
Fuel economy and CO2 output aren't the only factors to consider. Did they compare the NOx output between the two? NOx is a significant component of smog and acid rain. How about noise pollution?
I know, I know. It always comes down to the almighty dollar. Which one has the lowest COO? That's always the primary question of buyers, not how polluting the vehicle is.
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BlackbirdHighway 4:46PM (4/29/2008)
Money is important, but I think it's importance in choosing a vehicle is overstated. People will using a number of criteria in deciding what to buy. If that wasn't true, we would all be driving something like the Tata Nano.
I like the fact that the Merc handles better, but that woul dbe offset by the high cost of servicing. That's what turned me off to VW as well, servicing cost was outrageously high. I can do some things myself, but there is a lot of work that really needs a professional.
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MikeW 5:21PM (4/29/2008)
'real four wheel drive' NO, GM decided against the center differential.
Spare wheel-NO!
The hybrid tahoe could have so much better.
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Kevin Nugent 8:49PM (4/29/2008)
Hey does anybody else her ebut me see the rpoblem with this comparison . they are comparing the two most fuel efficent types of cars . Diesel and hybrid . Now what would happen if those technologies were combined together. A diesel hybrid car hmmmmm....... I think that 26 or 21 mpg rating for both vehicles woudl drastically jump . Possibly to the thirties. Low 31 or 32
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wxman 9:45PM (4/29/2008)
While NOx is required for ground-level ozone ("smog") formation, ambient conditions determine whether it creates ozone or destroys it. Urban areas are nearly exclusively VOC-limited, meaning that the amount of VOC emissions (which the Tahoe hybrid would almost certainly exceed the diesel, both directly and indirectly) would determine ozone levels. Reducing ambient NOx levels (at constant VOC levels) can actually cause ozone levels to be higher in these conditions due to the ozone-destruction capability of NOx.
As far as acid rain is concerned, NOx (as nitrate - NO3) does not correlate particularly well with rain water pH (see http://nadp.sws.uiuc.edu ). SOx (as sulfate - SO3) has a much better correlation.
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Chris Adams 8:05AM (4/30/2008)
I have a 2008 ML320 CDI. I drive 50% interstate (75MPH FL turnpike), 35% rural highways (60MPH), and the rest stuck at stoplights and in traffic (stop and go). I have averaged 27.2MPG for the past 16,000 miles, with a trend upwards over the past 5,000 miles as the vehicle gets broken in.
Diesel in Central FL can be had for $4.10 and right now premium will run about $3.90 (5% difference). Watch that cost advantage for gasoline vanish over the summer. Watch my vehicle settle in at 29MPG as it cruises past it's final break-in at 20K miles.
The V6 diesel engine from Mercedes Benz is an awesome engine, worth anyones time for a look-see. The 500 pounds less weight you get in the ML is also good for 0-60 times that are under 8 seconds (if you feel like squandering fuel), and the torque is beyond words at any speed.
Cheers!
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Throwback 8:24AM (4/30/2008)
The Tahoe hybrid uses regular not premium.
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Tom 12:48PM (4/30/2008)
Imagine that you, or better yet, your spouse and children, are in a horrific traffic wreck.
Would you rather they were in a vehicle that might leak diesel fuel all around them (which is very hard to ignite), or in a vehicle that may well bathe them in gallons of battery acid (explosive, eats flesh...). Oh, and by the way, when the rescue crews get there, they'll have to deal with high amperage DC current, if any of the batteries do remain intact.
No contest.
Then we get down to the sheer economics of it all.. It takes thousands of dollars in subsidies to make the hybrid cost competitive in the market, which means it isn't. And then the resale value. Which do you think will hold up better; a Mercedes diesel, the pinnacle of 100+ years of diesel development, or the latest cobbled together Rube Goldberg hybrid. Which do you think would be more reliable, less expensive to repair, etc.
As clean diesels (and I am all for clean, really) become more prevalent, hybrids become less and less attractive.
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XeroK00L 12:42PM (4/30/2008)
As someone above said, this review is unfair and incomplete without a test in city driving, where the hybrid shines.
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RipRip 12:40PM (5/02/2008)
I bet the diesel is carrying more battery acid than the hybrid, more than likely has far bigger 12v battery. My Civic hybrid barely uses the lead acid battery any more so it’s smaller to save weight.
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NG 1:09PM (5/03/2008)
The tahoe hybrid does not use Lead-Acid for the hybrid system. i believe it uses a nickel-based battery.
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Robyn 4:24AM (5/04/2008)
"Which do you think would be more reliable, less expensive to repair, etc."
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Are you serious? Mercedes and reliability don't exactly go together. They are always at the bottom of the reliability lists just as most European brands are. There is a reason Mercedes only offers a limited 48 months or 50,000 miles warranty compared to Gm's 60 Month 100,00 Mile warranty, which also fully covers the battery.
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